Auto engine diagnostic qeustion (NA)

Morgan3820

Morgan3820

Ejection Handle Pulled
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Daughter just purchased a 2017 Toyota Tacoma V6 with 140K miles. Very occasionally, at startup a very noticable white/grey plume emerges from the exhaust pipe. No particular smell. Have not had it long enough to determine any oil or coolant.usage.
Any ideas?
 
Take the radiator cap off and see if the coolant is oily/foamy. Sounds like a failing head gasket to me.
 
Yep sounds like moisture in the exhaust. Steam when the pipe gets warm enough. Excessive is hard to define.
 
Three votes for head gasket.
 
Soot in the exhaust pipe?
 
Pull the oil dip stick after the truck has been running a while--say 10 or 15 minutes of driving with the water temp up. If the oil on the stick looks like a milkshake or latte--likely head gasket.
 
A couple thing I have personally experienced and they relate to head gaskets.

1) As stated, look at your oil, if it is not oil color and has a milkshake consistency (you cant miss it) it is going to be a mixing of oil and coolant. This can be (usually is) a blown head gasket. Annoying, but not really hard to do. OR it can be a cracked head / block allowing the mixing. Head is less annoying than the block to deal with. OR it can be both head gasket and cracked head/block, but since you'd replace the gasket anyway in either case, nothing really added here.
2) Look at your coolant reservoir while the engine is running. If there are bubbles, it is likely a head gasket also.
* Surprise bonus thing*
3) If the head gasket has been recently replaced, it could still some coolant/oil mix in the exhaust track (manifold, catalytic converter, muffler, etc). Saw one that smoked bad after a head gasket replacement, but oil and coolant were fine. Took about 2 weeks for it to stop smoking on startup. Since your daughter just bought it, it is entirely possible it was bought w/ a blown head gasket to flip it and this is just a normal post replacement thing that will go away in a few days.
 
Hey guys, thanks for all the thoughtful responses. I was thinking head gasket.
 
Morgan3820 said:
Hey guys, thanks for all the thoughtful responses. I was thinking head gasket.
Click to expand...

I usually would not recommend a chemical attempt to fix this (if it is a head gasket) but some years ago after rebuilding a 318 Mopar engine it had a small head gasket leak (yes, new gaskets were used). I was told to try this product and amazingly enough it worked well. The use instructions are quite specific and it may not work in your case, but from my experience I think it's something you might consider:

www.moroso.com

CERAMIC ENGINE SEAL, 1 PT

Ceramic Engine Seal. One pint plastic bottle. Do not use with antifreeze
www.moroso.com www.moroso.com
 
A head gasket can fail in different ways leading to different symptoms. Are you noticing any symptoms other than that occasional and transient smoke? Overheating at all under stress or long idles? Does the cabin heater produce good heating? Loss of power?

Pressurize the radiator, take the oil fill cap off and listen for air. Does that Toyota have a coolant overflow tank? If so, get the engine warm and let it idle, then look in the overflow tank for bubbles in the coolant.

If ultimately you decide to keep it, you might consider simply replacing the motor. The way I look for parts such as that is: https://www.car-part.com/ which searches salvage yards efficiently.
 
I have lost an engine due to a head gasket failure ('86 S10 Blazer, 2.8L V6.) I probably should have just had it towed from the getgo but I didn't realize what happened until I got home, after letting the engine cool off.

That said, milky oil doesn't always mean head gasket failure. Short trips, particularly in the winter, can lead to condensation in the engine and milky oil appearance. That is particularly noticeable in motorcycles that have a clear glass sight window for the oil level.
 
If there's no milkshake in the oil/coolant other possibilities are old valve seals letting a bit of oil drip into the cylinders that burns off shortly after the next startup which can probably just be ignored if there's no significant oil consumption.
Another thought is it could be condensation in the exhaust- some mufflers have a weep hole for water to drain out, could get plugged. Drilling a very small hole in the muffler might let the water drain out in that case. I've had cars do this and make a HUGE plume from it- does it by any chance correlate with cool/cold mornings?
 
For $37 you can obtain this test kit:


You hold it in the radiator filler while the engine is running. If combustion gases (CO2) are present the blue fluid turns yellow or green. A little more scientific than looking for bubbles in the coolant.
 
Morgan3820 said:
Daughter just purchased a 2017 Toyota Tacoma V6 with 140K miles. Very occasionally, at startup a very noticable white/grey plume emerges from the exhaust pipe. No particular smell. Have not had it long enough to determine any oil or coolant.usage.
Any ideas?
Click to expand...
Is the cooling system filled with antifreeze (which would smell) or plain water (which would not)?
 
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